To identify differences in biologic and behavioral health outcomes among persons with chronic airflow limitation (CAL) who are either undernourished or adequately nourished. Specific aims are: l. Assess presence of increased metabolic rate in undernourished persons with CAL. 2. Assess the presence of increased skeletal muscle breakdown in undernourished persons with CAL. 3. Evaluate the relationship between altered metabolic conditions and behavioral out-comes for persons with CAL.